This application claims priority to Japanese patent application serial number 2001-385417, the contents of which are hereby incorporated by reference as if fully set forth herein.
1. Technical Field
The present teachings relate to intake manifolds for vehicles and more particularly, relate to techniques for improving the airtight seal of a short runner valve when the short runner valve is disposed in a closed position within the plenum of the intake manifold.
2. Description of the Related Art
Known intake manifolds include an air passage or plenum defined within the intake manifold and one or more short runner valves that are rotatably disposed within the air passage. The short runner valves rotate or pivot between an opened position and a closed position within the air passage. In some applications, the short runner valve may be required to tightly close or seal the air passage when the valve is disposed in the closed position. The short runner valve(s) may be utilized to adjust the tuning of the intake system over a wide range of engine speeds in order to deliver the appropriate amount of airflow to the combustion chambers (cylinders) of the vehicle engine and increase engine torque. That is, the short runner valves can be opened and closed to provide a supercharging or turbo effect and optimize engine torque output for a wide range of engine speeds. However, if air leaks through the short runner valve when the short runner valve is disposed in the closed position, the desired tuning can not be achieved and engine performance will suffer. Thus, it is a long felt-need to develop short runner valves that can reliably seal the air passage during operation of the intake manifold.
Japanese Laid-Open Patent Publication No. 7-279696 discloses a technique for increasing the airtight seal of a valve. As shown in FIG. 5, the known valve 51 includes rubber seals 52, 53 that are affixed to the respective outer edges of valve 51. Body (plenum) 56 defines aperture 57 and the valve 51 is pivotably disposed within aperture 57. In addition, body 56 defines sealing faces 54, 55. FIG. 5 shows the state in which valve 51 is disposed in the closed position with respect to aperture 57. Further, aperture 57 is opened when valve 51 is pivoted or rotated counterclockwise from the closed position.
If positive pressure is applied to the valve 51 in the direction shown by arrows 58, 59 when valve 51 is disposed in the closed position, the positive pressure presses sealing members 52, 53 against the respective sealing faces 54, 55. Thus, sealing members 52, 53 effectively prevent air leaks through aperture 57 and the known valve 51 can realize an airtight seal under this condition.
However, if positive pressure is applied to valve 51 in the direction of arrows 60, 61 (i.e., in the direction that is opposite of arrows 58, 59), sealing members 52, 53 will be forcibly separated from the respective sealing faces 54, 55 by the applied pressure and air will leak through aperture 57. Therefore, the known valve 51 can only ensure an airtight seal for pressure applied to one side of valve 51 and air may be caused to leak through aperture 57 when positive pressure is applied to the opposite side of valve 51.
Accordingly, it is one object of the present teachings to provide valves that maintain a substantially airtight seal regardless of the direction in which positive pressure is applied to the valve.
In one aspect of the present teachings, air intake manifolds may include a body or plenum and an air passage defined within the body. A sealing face may be defined on a flange that projects into an aperture defined within a partition wall. The air intake manifolds may further include at least one short runner valve (or SRV) that is disposed within the aperture such that the SRV can be pivoted or rotated between an opened position and a closed position. An elastic sealing member may be affixed to the periphery (e.g., peripheral edge) of the SRV. The sealing member may include a first portion that presses against (contacts) the sealing face when pressure is applied to one side of the closed SRV. The sealing member also may include a second portion that presses against (contacts) the sealing face when pressure is applied to the opposite side of the closed SRV. Thus, at least one sealing portion will be pressed against the sealing face regardless of the direction of the applied pressure, thereby providing a reliable airtight seal under all operating conditions.
In another aspect of the present teachings, the SRV may be substantially plate-shaped and the elastic sealing member may be affixed or attached to a peripheral edge of the plate-shaped valve. The first and second portions of the sealing member may be first and second projections that extend or project from the periphery of the plate-shaped valve. The first and second projections may form a substantially V-shape in cross section and the V-shaped opening preferably faces the sealing face. When the plate-shaped valve is rotated towards the closed position, the V-shaped projections will closely contact the sealing face regardless of which direction that pressure is being applied to the SRV.
That is, when positive pressure is applied to one side of the plate-shaped valve, the first projection will be pressed against the sealing face. On the other hand, when positive pressure is applied to the opposite side of the valve, the second projection will be pressed against the sealing face. Therefore, reliable airtight seals may be ensured for the SRV in both directions that pressure may be applied to the SRV.